CSE 2011 Lecture 5

 

Testing and Debugging

• Create a test plan application that will probe the program with input and compare its output to see if the program is outputting the desired output from the test
  
• Verification
  
  • Does the software meet its specifications
    
• Validation
  
  • Does the software meet its requirements
    
• Identify test criteria
  
  • What are the goats for comparing the system against its spec
    
    • Reliability, completeness, robustness
      
  • Identify target components for testing
    
    • In an OO system the classes and class hierarchies
      
  • Generate test cases
    
    • Produce test cases that can identify faults in an implementation
      
  • Execute test cases against target components
    
  • Evaluation
    
    • If expected outputs are not produced, a bug report is issued
      
• Black box testing
  
  • Testing based on input and output alone
    
    • Do not consider underlying implementation
      
  • Test cases are generated from the spec
    
    • Pre and post conditions
      
  • Specific kinds of black box testing
    
    • Random testing
      
      • Generate random inputs
        
      • Easy to generate cases
        
      • Good at detecting failures
        
      • Must be able to easily generate expected output
        
    • Partition testing
      
      • Cannot try all possibly inputs
        
        • Partition input into equivalence classes
          
        • Every value in a class should behave similarly
          
      • Test cases
        
        • Just before the boundary
          
        • Just after the boundary
          
        • On a boundary
          
        • One from the middle of an equivalence class
          
      • Loops
        
        • Zero times through the body
          
        • Once through the body many times through the body